(88 days)
This device is indicated for:
- Moderate to severe knee instability
- Significant bone loss and/or ligament deficiencies caused by neoplasms, trauma, rheumatoid arthritis, osteoarthritis, traumatic arthritis, collagen disorders, and/or avascular necrosis of the proximal and/or distal femur and/or proximal tibia.
- Valgus, varus or flexion deformities
- The salvage of previously failed surgical attempts
- A total femoral replacement construct consisting of the MOST Options® or Segmental proximal femoral, Segmental System segments and Segmental System distal femoral components may be used without cement.
- Variable Stiffness stem extensions require the use of either a smooth or Trabecular Metal stem collar, which must be cemented to the stem. Following cementing to the stem, the smooth collar must be cemented against the bone. The remainder of the stem must be used uncemented.
- Fluted stem extensions require the use of either a smooth or Trabecular Metal stem collar, which must be cemented to the stem. Following cementing to the stem extension, the smooth collar must be cemented against the bone. The remainder of the stem must also be cemented against the bone.
- The Trabecular Metal collar may be used cemented or uncemented against the bone.
- All other constructs are for cemented use only.
The Zimmer Segmental System is intended to replace the proximal femur, mid-shaft femur, distal femur, proximal tibia and/or total knee in cases that require extensive resection and restoration. The Segmental System provides for cross compatibility between selected components from the MOST Options® System and NexGen® Rotating Hinge Knee System. A total mid-calf to hip replacement can be achieved using the Segmental System. The cleared distal femoral component and the proposed proximal tibial component are designed to be compatible with standard NexGen patella components. The proximal femoral components are designed to be compatible with various Zimmer femoral heads with a 12/14 taper.
The Trabecular Metal Proximal Femoral Component is designed to replace the proximal femur and is available in two sizes (38mm and 46mm offsets). The Trabecular Metal Proximal Tibial Component is designed to replace the proximal tibia and is available in three sizes. The Segment with Male/Female Taper components are designed to be used with Segmental System Stem Extensions in combination with a proximal femoral component, a distal femoral component, and/or a proximal tibial component, or intercalary segments, in order to replace portions of the proximal femur, mid-shaft femur, distal femur, and/or proximal tibia.
Here's an analysis of the provided text regarding the acceptance criteria and study for the Zimmer Segmental System Trabecular Metal components:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion | Reported Device Performance |
|---|---|
| Equivalence to Predicate Devices (Intended use, materials, sterility, performance characteristics) | "The proposed Segmental System components are similar or identical in intended use, materials, sterility, and performance characteristics to the predicate devices." |
| Safety and Effectiveness | "The results of non-clinical (lab) performance testing demonstrate that the devices are safe and effective and substantially equivalent to the predicate devices." |
| Proximal Femoral Component Fatigue Test | Successful (implied by "demonstrate that the devices are safe and effective and substantially equivalent") |
| Proximal Tibial Component Fatigue Test | Successful (implied by "demonstrate that the devices are safe and effective and substantially equivalent") |
| Segment Component Fatigue Test | Successful (implied by "demonstrate that the devices are safe and effective and substantially equivalent") |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: Not specified. The document states "Non-Clinical Performance and Conclusions: The results of non-clinical (lab) performance testing demonstrate..."
- Data Provenance: The testing was "non-clinical (lab) performance testing." The country of origin is not explicitly stated, but the sponsor is Zimmer, Inc.
- Retrospective or Prospective: Not applicable as it's non-clinical lab testing.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- This information is not applicable. The study described is non-clinical (lab) performance testing and does not involve human expert ground truth for medical imaging or diagnostics. It assesses the mechanical performance of the device.
4. Adjudication Method for the Test Set
- Not applicable as the study involves non-clinical lab testing, not human-based adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No. An MRMC study was not done. The document explicitly states: "Clinical data and conclusions were not needed for this device." This type of study typically involves human readers a device (like AI) against human performance.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study Was Done
- Not applicable. This device is a medical implant (prosthesis components), not an algorithm or AI software. Therefore, the concept of a "standalone" algorithmic performance study does not apply. The performance evaluated is the mechanical performance of the physical device itself.
7. The Type of Ground Truth Used
- The "ground truth" for this non-clinical testing would be the engineering specifications and scientific principles governing mechanical fatigue and material properties relevant to the intended use of the prosthetic components. The tests verify that the device meets these pre-defined engineering standards.
8. The Sample Size for the Training Set
- Not applicable. This device is hardware, not an AI algorithm. There is no concept of a "training set" in this context.
9. How the Ground Truth for the Training Set Was Established
- Not applicable. As above, there is no training set for this hardware device.
Summary of the Study:
The study described is focused on demonstrating substantial equivalence of the Zimmer Segmental System Trabecular Metal components to predicate devices through non-clinical (lab) performance testing. The specific tests mentioned are:
- Proximal femoral component fatigue test
- Proximal tibial component fatigue test
- Segment component fatigue test
The conclusion drawn from these tests is that the devices are safe and effective and substantially equivalent to the predicate devices. No clinical data or human reader studies were deemed necessary for this 510(k) clearance.
§ 888.3510 Knee joint femorotibial metal/polymer constrained cemented prosthesis.
(a)
Identification. A knee joint femorotibial metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace part of a knee joint. The device limits translation or rotation in one or more planes and has components that are linked together or affined. This generic type of device includes prostheses composed of a ball-and-socket joint located between a stemmed femoral and a stemmed tibial component and a runner and track joint between each pair of femoral and tibial condyles. The ball-and-socket joint is composed of a ball at the head of a column rising from the stemmed tibial component. The ball, the column, the tibial plateau, and the stem for fixation of the tibial component are made of an alloy, such as cobalt-chromium-molybdenum. The ball of the tibial component is held within the socket of the femoral component by the femoral component's flat outer surface. The flat outer surface of the tibial component abuts both a reciprocal flat surface within the cavity of the femoral component and flanges on the femoral component designed to prevent distal displacement. The stem of the femoral component is made of an alloy, such as cobalt-chromium-molybdenum, but the socket of the component is made of ultra-high molecular weight polyethylene. The femoral component has metallic runners which align with the ultra-high molecular weight polyethylene tracks that press-fit into the metallic tibial component. The generic class also includes devices whose upper and lower components are linked with a solid bolt passing through a journal bearing of greater radius, permitting some rotation in the transverse plane, a minimal arc of abduction/adduction. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.